1. Human-to-Human Communication A model for human-computer interaction? Important scope limitation: problem solving Why look at human-human interface? – The human-computer interface is really a human- human interface because a computer’s intellectual substance is wholly derived from people! 1

2. Human-to-Human Communication – Computer messages are messages from human designers to human users: Offset in time Sent through a “mask” – Lowers inhibitions – Can bring out hostility or misdirected sense of humor – A phenomenon observed by sociologists in actors Wrap up 2

3. Human-to-Human Communication Chapanis did study of nature of human- human communication for problem solving A. Chapanis, Scientific American, 1975. – Source and seeker of information – Neither can solve problem alone – Must work together – Problem: assemble a trash toter Wrap up 3

4. Human-to-Human Communication Communication channels – Voice – Hand-writing – Typing – Video Communication mode – combination of channels The experimental setup (next slide) Wrap up 4

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6. Excerpt from typed communication Wrap up 6

7. Excerpt from voice communication Wrap up 7

8. Human-to-Human Communication Results – Order of efficiency (time to solve) Communication-rich mode (all channels) Voice (but cannot see each other) Hand-writing (including drawing sketches) Typing (experienced) Typing (inexperienced) – Time to complete From less than 30 minutes (communication-rich mode) to over 60 minutes (factor of 2.5) Wrap up 8

9. Human-to-Human Communication Results – Unexpected aspects Small difference between experienced and inexperienced typists – Only about 1/3 of time on average used in typing – Different kind of typing (abbreviated and without attention to punctuation) Small difference between communication-rich and voice only – In spite of all the information-bearing gestures Voice was most important channel – All modes with voice did substantially better Wrap up 9

10. Human-to-Human Communication Observations – Communication was very ungrammatical A big barrier to voice I/O in HCI Almost unintelligible Expected, but surprising in extent that it was true Communication success is tribute to human ability Wrap up 10

11. Human-to-Human Communication Observations – Voice channels are very verbose Higher bandwidth got used, but not efficiently – Allowing interruption Did not shorten solution time Does cause different message packaging Wrap up 11

12. Human-to-Human Communication In-class exercise – Everyone: as you observe, write down important characteristics of human-human-communication for problem-solving – Are these not also important in human-computer interaction? Wrap up 12